[poetry plugin] ensure initHook runs with /bin/sh

[savil]

Summary

A user is saying that the poetry plugin's init-hook was failing for them with Fish
shell. While the init-hook's command does work with modern fish shells, it fails
for older versions of fish.

In this case, the user is on Ubuntu whose package manager seems to use an older
version of fish.

Regardless, we can ensure the plugin's init-hooks work for consistently if we
ensure that they are written as posix scripts executed via /bin/sh. This PR
seeks to do that.

Fixes #1550

How was it tested?

cd examples/development/poetry/poetry_demo
devbox run run_test

[savil]

Current dependencies on/for this PR:

• main
  • PR [poetry plugin] ensure initHook runs with /bin/sh #1553 👈

This comment was auto-generated by Graphite.

[mikeland73]

Should all init hooks run in bash? I'm not sure we can claim devbox.json is portable if they don't.

[savil]

@mikeland73 currently, we state that the init-hooks run in the shell they are imported into. For devbox shell, this is the user's shell. For devbox scripts, this is sh.

I think changing init-hooks to always run in sh makes sense for portability. OTOH it would be a breaking change since some users may have written init-hooks that work just fine in their shells, but are not portable for sh. So, we need some plan for introducing this change gradually.

Perhaps this could be introduced as part of a move of init-hooks out of the "shell" field in devbox.json. If its an opt-in migration process, or a new devbox.json field, then we can insist that the new init-hooks field run in sh. Can discuss more IRL.

[savil]

Ugh, this won't solve the problem. I misunderstood how sourcing works in shells. Will send an update to fix this for older fish shells.